In theory, this should have been a good moment for Britain's United Kingdom Independence Party (UKIP). The political party had long campaigned for Britain to leave the European Union, and last year its dreams came true. Now, less than a year after finding out that its anti-E.U. and anti-elite message held sway over large parts of the country, Britain is going to vote in a contentious early election. Why wouldn't some vote for UKIP?

However, things aren't going so well. It turns out that post-Brexit, UKIP is struggling to define what its broader political message is. Case in point: This weekend, the party announced it would seek to ban the burqa and other Islamic veils. But despite polls that show widespread support for the move, it has proven so controversial in Britain that high-profile supporters of the party have publicly broken with it — leaving the party reeling just weeks ahead of a key election.

UKIP leader Paul Nuttall, 40, first announced the proposal during an interview with the BBC's Andrew Marr on Sunday. Nuttall said that full-face veils were a security problem and claimed that they prevented the Muslim women who wore them from fully taking part in British life. "What we need to do is ensure these people are fully integrated into British society," the UKIP leader said, "and you can't do that from behind a veil."

According to Nuttall, the proposal would be similar to bans on veils already in place in place in parts of Europe. UKIP is also seeking other laws that could impact some of Britain's 2.9-million-strong Muslim minority, including limits on the use of Islamic sharia law and a legal requirement to report evidence of female genital mutilation, the BBC reported.

The proposal prompted an immediate backlash from liberal politicians. “Sorry, Britain won't be taking any lessons on integration from hate peddlers," tweeted Chuka Umunna, a member of Parliament from the center-left Labour Party. Green Party leader Caroline Lucas called UKIP's proposals “full-throttled Islamophobia.”

UKIP members quickly faced multiple questions about how a ban on face-covering might work in practice. The party was forced to clarify at a press event Monday that beekeepers would not be affected by the proposal. In an interview with Sky News, Nuttall also specified that the ban would not cover “big hats.”

However, the most damning reaction came from those directly allied with the party.

Aaron Banks, a high-profile multimillionaire who used to be one of the party's major donors, swiftly distanced himself from the proposal, telling the BBC on Sunday that he was “personally not in favor of that” and that “people had a right to their religious beliefs.” Banks went further on Tuesday as he announced that he would be withdrawing his application to run as a UKIP candidate in June's election.

“Not sure campaigning with the national party going in entirely the wrong direction is smart,” Banks wrote on Twitter. “I don’t approve of the war on Muslim religion.”

That wasn't the only major blow. UKIP's foreign affairs spokesman announced that he, too, would be leaving the party due to the policy. "I would be one of the first to condemn a ban on wearing a crucifix as an infringement of liberty," James Carver, a UKIP member of the European Parliament, wrote in a statement published Thursday. "No one has the right to dictate what people should wear."

Another European Parliament member, David Coburn, also weighed in. “In a fair and democratic society everyone can wear whatever articles of clothing or of Faith they wish,” Coburn, who also serves as UKIP's Scottish leader, wrote on Twitter.

The rift is another setback for UKIP after its only member of the British Parliament quit the party last month, with polls suggesting a struggle in the upcoming general election. Nuttall has faced criticism for his leadership style since succeeding Nigel Farage as party leader in November. He lost his February bid for a seat in Parliament in a by-election in a pro-Brexit constituency, in part due to accusations that he had exaggerated his ties to the 1989 Hillsborough disaster, in which 96 people died in an overcrowded soccer stadium. Nuttall, who currently serves as a member of the European Parliament, has not fully committed to running in June.

Nuttall had promised to broaden UKIP's appeal beyond the scope of Brexit-related politics, long the bread and butter of the party's support. He may have hoped that a proposed burqa ban might have helped here: Some polls have suggested that as many as 57 percent of British voters would support the proposal, including a remarkable 84 percent of UKIP voters. Similar bans have also been implemented in a number of areas in mainland Europe, most notably in France, although major questions have been raised about the effectiveness of the French law.

However, UKIP exists in a different political world than many of its peers on the continent. Most notably, the history of the state's relationship with religion is very different from France. In 2013, Nuttall himself distanced the party from previous calls for a burqa ban. “What we wouldn’t go down the line of is forcing a blanket ban," he said in an interview with the Huffington Post. "We are a libertarian party."